FIG. 10 illustrates a semiconductor pressure sensor device according to the related art illustrated in FIG. 1 of JP 4281178 B (Patent Document 1) with the reference numerals increased by 100 from those allocated to the counterparts of the Patent Document 1. The semiconductor pressure sensor device according to the related art includes a first case 120, leads 130, a second case 140, and a surrounding portion 142. The first case 120 is molded from a resin. A sensor element constituted of a semiconductor is disposed in the first case 120. The leads 130 are insert-molded in the first case 120 such that portions of the leads 130 are exposed from the first case 120, and electrically connected to the sensor element. The second case 140 is assembled with the first case 120 to cover the sensor element. The surrounding portion 142 is formed on the second case 140 to surround the exposed portions of the leads 130. The exposed portions of the leads 130 and the surrounding portion 142 constitute a connector portion that enables the exposed portions of the leads 130 to be connected to external terminals. The first case 120 and the second case 140 slide to fit with each other. An engagement structure (125, 147) is provided between the first case 120 and the second case 140 for retention. The first case 120 is integrally provided with a cylindrical body 121 into which a fluid to be measured flows.